This presentation explains how we survey birds that are difficult to monitor such as Eagle Owls and other owl species, Gold Eagles, Peregrine Falcons and other raptors. This method, using acoustic recorders, can also be used to survey other bird species and is a complement to other types of surveys e.g when trying to identify nesting birdfauna in an area. Examples of recordings will be played during the presentation which will focus on Eagle Owls and Golden Eagle surveys.